A transmission electron microscope that accelerates an electron beam emitted from an electron source, irradiates a specimen with the electron beam, and detects electrons transmitted through the specimen can quantitatively measure an electromagnetic field of a substance or in a vacuum by measuring a change in the electron beam resulting from interaction between the electron beam and the electromagnetic field of the specimen. As representative methods of measuring the electromagnetic field using an electron beam, electron beam holography (Patent Document 1) that obtains interference fringes of electrons using electron beam biprisms, a method (Non-Patent Document 1) that determines an electromagnetic field from a change in a two-dimensional intensity distribution of microscope images obtained by changing a focal point of an electron microscope, and a method (Non-Patent Document 2) that determines an effect that an electromagnetic field deflects an electron beam transmitted by a specimen from positions of electrons arriving at an electron detector are known. Furthermore, a magnetic field application technique, to be described later, is disclosed in Patent Documents 2, 3, 4, and the like.